local util = require 'lspconfig.util'
local M = {}

local function reload_workspace(bufnr)
  bufnr = util.validate_bufnr(bufnr)
  vim.lsp.buf_request(bufnr, 'rust-analyzer/reloadWorkspace', nil, function(err)
    if err then
      error(tostring(err))
    end
    vim.notify 'Cargo workspace reloaded'
  end)
end

M.config_table = function (attach, capabilities)
  return {
    default_config = {
      cmd = { 'rust-analyzer' },
      filetypes = { 'rust' },
      attach = attach,
      capabilities = capabilities,
      root_dir = function(fname)
        local cargo_crate_dir = util.root_pattern 'Cargo.toml'(fname)
        local cmd = { 'cargo', 'metadata', '--no-deps', '--format-version', '1' }
        if cargo_crate_dir ~= nil then
          cmd[#cmd + 1] = '--manifest-path'
          cmd[#cmd + 1] = util.path.join(cargo_crate_dir, 'Cargo.toml')
        end
        local cargo_metadata = ''
        local cargo_metadata_err = ''
        local cm = vim.fn.jobstart(cmd, {
          on_stdout = function(_, d, _)
            cargo_metadata = table.concat(d, '\n')
          end,
          on_stderr = function(_, d, _)
            cargo_metadata_err = table.concat(d, '\n')
          end,
          stdout_buffered = true,
          stderr_buffered = true,
        })
        if cm > 0 then
          cm = vim.fn.jobwait({ cm })[1]
        else
          cm = -1
        end
        local cargo_workspace_dir = nil
        if cm == 0 then
          cargo_workspace_dir = vim.fn.json_decode(cargo_metadata)['workspace_root']
        else
          vim.notify(
            string.format('[lspconfig] cmd (%q) failed:\n%s', table.concat(cmd, ' '), cargo_metadata_err),
            vim.log.levels.WARN
          )
        end
        return cargo_workspace_dir
          or cargo_crate_dir
          or util.root_pattern 'rust-project.json'(fname)
          or util.find_git_ancestor(fname)
      end,
      settings = {
        ['rust-analyzer'] = {},
      },
    },
    commands = {
      CargoReload = {
        function()
          reload_workspace(0)
        end,
        description = 'Reload current cargo workspace',
      },
    },
    docs = {
      description = [[
  https://github.com/rust-analyzer/rust-analyzer
  rust-analyzer (aka rls 2.0), a language server for Rust
  See [docs](https://github.com/rust-analyzer/rust-analyzer/tree/master/docs/user#settings) for extra settings.
      ]],
      default_config = {
        root_dir = [[root_pattern("Cargo.toml", "rust-project.json")]],
      },
    },
  }
end

return M
